Using Aliyun centos7.6 supervisor to deploy flask project, calling database always reports exception SystemExit: 1 - Codes Helper

deploy the flask project using centos7.6 supervisor, and the calling database always reports an exception SystemExit: 1
the exception code posted below
2018-12-25 20:59:46 [15759:/Website/Pilot/app/v0_1/user/view.py:127] [ERROR] code_login Traceback (most recent call last):
  File "/Website/Pilot/app/v0_1/user/view.py", line 100, in register
    user = user_svr.get_user_by_email(email=email)
  File "/Website/Pilot/services/user/user_service.py", line 25, in get_user_by_email
    return self.db.query(YyUserDo).filter(YyUserDo.email == email, YyUserDo.deleted == 0).first()
  File "/Website/dhenv/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 2755, in first
    ret = list(self[0:1])
  File "/Website/dhenv/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 2547, in __getitem__
    return list(res)
  File "/Website/dhenv/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 2855, in __iter__
    return self._execute_and_instances(context)
  File "/Website/dhenv/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 2876, in _execute_and_instances
    close_with_result=True)
  File "/Website/dhenv/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 2885, in _get_bind_args
    **kw
  File "/Website/dhenv/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 2867, in _connection_from_session
    conn = self.session.connection(**kw)
  File "/Website/dhenv/lib/python2.7/site-packages/sqlalchemy/orm/session.py", line 998, in connection
    execution_options=execution_options)
  File "/Website/dhenv/lib/python2.7/site-packages/sqlalchemy/orm/session.py", line 1003, in _connection_for_bind
    engine, execution_options)
  File "/Website/dhenv/lib/python2.7/site-packages/sqlalchemy/orm/session.py", line 403, in _connection_for_bind
    conn = bind.contextual_connect()
  File "/Website/dhenv/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 2112, in contextual_connect
    self._wrap_pool_connect(self.pool.connect, None),
  File "/Website/dhenv/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 2147, in _wrap_pool_connect
    return fn()
  File "/Website/dhenv/lib/python2.7/site-packages/sqlalchemy/pool.py", line 387, in connect
    return _ConnectionFairy._checkout(self)
  File "/Website/dhenv/lib/python2.7/site-packages/sqlalchemy/pool.py", line 766, in _checkout
    fairy = _ConnectionRecord.checkout(pool)
  File "/Website/dhenv/lib/python2.7/site-packages/sqlalchemy/pool.py", line 516, in checkout
    rec = pool._do_get()
  File "/Website/dhenv/lib/python2.7/site-packages/sqlalchemy/pool.py", line 1138, in _do_get
    self._dec_overflow()
  File "/Website/dhenv/lib/python2.7/site-packages/sqlalchemy/util/langhelpers.py", line 66, in __exit__
    compat.reraise(exc_type, exc_value, exc_tb)
  File "/Website/dhenv/lib/python2.7/site-packages/sqlalchemy/pool.py", line 1135, in _do_get
    return self._create_connection()
  File "/Website/dhenv/lib/python2.7/site-packages/sqlalchemy/pool.py", line 333, in _create_connection
    return _ConnectionRecord(self)
  File "/Website/dhenv/lib/python2.7/site-packages/sqlalchemy/pool.py", line 461, in __init__
    self.__connect(first_connect_check=True)
  File "/Website/dhenv/lib/python2.7/site-packages/sqlalchemy/pool.py", line 651, in __connect
    connection = pool._invoke_creator(self)
  File "/Website/dhenv/lib/python2.7/site-packages/gunicorn/workers/base.py", line 192, in handle_abort
    sys.exit(1)
SystemExit: 1
which god will help me to see what the problem is